Valve cups and containers for use in fluid medium dispensing systems

ABSTRACT

The present invention provides a valve cup (10) for use with a container (30) for dispensing a fluid medium stored under pressure. The valve cup (10) supports a valve (50) and seals an opening (32) of the container (30) and is formed from a semi-crystalline polyester. The present invention also provides a container (30), wherein at least a part of the container (30) surrounding an opening (32) is formed from a semi-crystal-line polyester. A further valve cup (10) is formed from a metal or rigid material and further includes a polyester lining (70). Dispensing systems (1) including the above containers (30) and valve cups (10) are provided, wherein welding is facilitated between the container (30) and valve cups (10).

The invention relates to an improvement in sealing performance andattachment between a valve cup and a container for dispensing a fluidmedium stored under pressure. A method for assembling a system fordispensing a fluid medium stored under pressure is also described.

BACKGROUND

Systems for dispensing a fluid medium stored under pressure aregenerally well-known. Many systems dispense aerosols, such as deodorantor paint, generally as a fine spray. However, any fluid medium may bestored and dispensed, e.g., shampoo, etc.

Typical systems include a container, a valve, and a valve cup, whereinthe valve cup supports the valve usually at a central part thereof andalso closes off an opening of the container. The inner volume of thecontainer is usually pressurised and maintained in such a state by thevalve and the seals between the valve cup and valve, and valve cup andcontainer opening. When the valve is actuated, the pressure differencebetween the inner volume of the container and the outside environmentcauses the fluid medium to be expelled from the container. Some systemsemploy a two-stage container having an inner and outer container, one ofwhich contains the propellant gas, whereas others may employ a singlecontainer with the fluid medium also acting as the propellant.

Traditionally, the containers are made from a metal, usually aluminium.Recently, there has been an increasing trend to use plastics, namelypolyethylene terephthalate (PET), as the containers for these dispensingsystems for various advantages such as cost and ease of manufacturing,among others. The systems should be stable and be able to withstand theinternal pressures of the container while also providing an adequateseal.

Conventional systems employing PET containers also typically use ametal, e.g., aluminium, for the valve cups which ensures a suitablesealing engagement between the valve cup and valve. The valve cup may beclinched to a lip of the opening of the container. While the attachmentbetween the valve cup and container is often sufficient at most normaloperating temperatures, higher temperatures can cause the PET containerto deform to a large degree such that the connection between thealuminium valve cup and container opening is no longer fluid tight. Thisis highly disadvantageous as the propellant gas and/or the fluid mediumcan escape from the container.

DE 37 37 265 A1 proposes a solution to this problem by additionallyforming the valve cup from a plastic, such as PET. In this case, thevalve cup can be welded, e.g., friction welded, to the container becausethe valve cup and container are made of the same or similar materials.At high temperatures, the weld is sufficient to maintain the sealbetween the valve cup and the container.

European safety requirements specify that aerosol systems should not beexposed to temperatures above 50° C. However, in practice, suchdispensing systems may be subject to much higher temperatures. In thecase of DE 37 37 265 A1, the disclosed device does not providesufficient sealing performance at temperatures exceeding 50° C. becausethe plastic valve cup may also deform at these temperatures to theextent that the seal between the valve cup and valve is lost.

A dispensing system exhibiting sufficient sealing performance attemperatures greater than 50° C. is therefore required. Herein,temperatures greater than 50° C. should be understood as reasonabletemperatures that the dispensing system might be exposed to, e.g., up to100° C.

SUMMARY

The problem is solved by a valve cup for use with a container fordispensing a fluid medium stored under pressure, the valve cup adaptedto support a valve and to seal an opening of the container, wherein:

-   -   the valve cup is formed from a first plastic material that is a        semi-crystalline polyester.

A valve cup is a component that supports a valve and is placed so as tocover the opening of a container suitable for containing a fluid mediumto be dispensed. Semi-crystalline polyesters have a greater degree ofcrystallinity compared to more amorphous polyesters. As a result,semi-crystalline polyesters typically do not deform when exposed totemperatures greater than 50° C., at least as compared with amorphouspolyesters. In this way, structural rigidity of the valve cup can beimproved at higher temperatures meaning that the seal between the valveheld by the valve cup and the valve cup is maintained.

A further embodiment provides the valve cup above, wherein the firstplastic material has a degree of crystallinity greater than 35%,preferably greater than 38%, when measured using differential scanningcalorimetry.

The degree of crystallinity is one property that provides the plasticmaterial with its rigidity at higher temperatures. Typically, plasticsmay have some percentage of amorphous regions and some percentage ofcrystallised regions. When exposed to high temperatures, the amorphousregions undergo a transition from a hard and brittle state to a morerubbery and soft state. Thus, it can be considered that the amorphousregions lead to deformation of the plastic at greater temperatures.Providing a material with a higher degree of crystallinity may reducethe degree of deformation of the plastic material at highertemperatures.

As a further note, the degree of crystallinity is generally measuredwith respect to a certain method—here it is given as differentialscanning calorimetry (DSC). Generally, various methods may give slightlydifferent results because the degree of crystallinity is essentially anaverage value. When using other methods, an appropriate scaling shouldbe taken into consideration with respect to the value obtained by DSC.

Another embodiment provides any of the valve cups above, wherein thefirst plastic material is selected from the group consisting of:crystallised PET, PBT, PEN, PEN/PET copolymers, or a blend of any of theforegoing.

Crystallised PET (CPET), PBT, PEN, and PEN/PET copolymers are or can besemi-crystalline polyesters. These materials are particularlyadvantageous for their other properties in packaging and not just therigidity at elevated temperatures. However, any polyester that can besemi-crystalline and does not deform to a suitable degree at largetemperatures may also be used as the semi-crystalline material.Moreover, any blend of CPET, PBT, PEN, and PEN/PET may be used as thefirst plastic material. In a preferred embodiment, PBT is used as thefirst plastic material.

Another embodiment provides any of the valve cups above, wherein thevalve cup comprises a central opening that is adapted to receive andsupport the valve. The valve cup also comprises one or more enforcingmembers radially protruding from the central opening, wherein the one ormore enforcing members are adapted to increase the rigidity of the valvecup.

Enforcing members may be provided on a surface of the valve cup andextend in a radial direction from a location where the valve issupported. The enforcing members may be made of the same material as thevalve cup or a different material. The enforcing members may increasethe rigidity of the valve cup in a mechanical sense by directing orchannelling any deformation. The enforcing members may be integrallyformed with the valve cup or separate components and attached thereto.

A further embodiment comprises any of the above valve cups, wherein thevalve cup further comprises an inverted U-shaped receiving portionconfigured to receive a lip portion of the container.

The inverted U-shaped receiving portion can be provided on an outersurface or diameter of the valve cup and is preferably shaped and sizedto receive a lip portion of the container. In this manner, the valve cupcan be reliably positioned with respect to the container and can besuitably attached via, for example, welding.

Yet another embodiment provides any of the valve cups above, inparticular directly above, wherein the inverted U-shaped receivingportion comprises at least one protrusion on a surface facing thecontainer when receiving the lip portion, the protrusion adapted tofrictionally engage the lip portion.

The inverted U-shaped receiving portion may be provided with at leastone protrusion to aid in fixing, at least temporarily, the valve cup tothe container to thereby facilitate the welding without concern of thevalve cup being displaced.

The problem is also solved by a fluid medium dispensing systemcomprising:

-   -   a container for storing a fluid medium under pressure, the        container comprising an opening;    -   a valve; and    -   any of the valve cups above further adapted to support the valve        and seal the opening of the container, wherein    -   the container is formed from a second plastic material, and    -   the first plastic material is weldable to the second plastic        material.

Reliable sealing may be achieved not only by providing a rigid valve cupin order to maintain the seal between the valve cup and the valve, butalso by ensuring that the container is suitably sealed to the valve cup.Plastic containers may be advantageous for various reasons compared tometal containers, e.g., because of cost or ease of manufacturing.However, some plastic containers may be prone to deformation at highertemperatures, e.g., conventional PET used for bottles. A plastic valvecup permits welding to the plastic container. Therefore, even if thecontainer deforms, the container is fixed to the valve cup in such a waythat the seal therebetween is not broken. In other words, the sealbetween the valve cup and container is maintained. Hence, a rigidplastic valve cup provides the ability to make use of the advantages ofplastic containers, while maintaining the seal between the valve andvalve cup.

In one embodiment of the system above, the second plastic material is apolyester, preferably PET.

Polyesters, and in particular PET, have many advantageous qualities inpackaging applications. They can be easy to manipulate and thus formingvalve cups and containers may be relatively easier and quicker. In somecases, the polyesters may also be relatively cheap. Some polyesters canalso be recycled thus reducing the overall overhead cost. Finally, somepolyesters can also be sterilised which is particularly advantageous formedical applications.

A further embodiment provides any of the systems above, wherein thevalve cup is weldable to the container by one of: friction welding,ultrasonic welding, and laser welding.

When using plastics and pressurised containers, it is advantageous toemploy any of the welding methods above. Preferably, the welding used inthe system above provides a chemical bond between the valve cup andcontainer that can withstand the forces that may be experienced due todeformation of the container at higher temperatures.

A further embodiment provides any of the systems above, wherein thevalve cup is welded to container, thereby providing a seal between thevalve cup and the opening of the container.

In some cases, the valve cup and container may be provided separately toenable undercup gassing when pressurising the inner volume of thecontainer.

The problem is also solved by a container for dispensing a fluid mediumstored under pressure and comprising an opening, the container for usewith a valve cup supporting a valve sealing the opening of thecontainer, wherein

-   -   at least a part of the container adjacent the opening is formed        from a first plastic material that is a semi-crystalline        polyester.

In an alternative to the embodiments above, at least a part of thecontainer may be formed from the semi-crystalline materials. Preferably,this part is adjacent or in contact with the opening of the container.In this way, when the container experiences elevated temperatures, thepart adjacent or in contact with the opening does not deform. In otherwords, at elevated temperatures, the opening maintains its shape. Inthis way, any seal with the valve cup can be maintained.

A further embodiment provides the container above, wherein the firstplastic material has a degree of crystallinity greater than 35%,preferably greater than 38%, when measured using differential scanningcalorimetry.

Another embodiment provides any of the containers above, wherein thefirst plastic material is selected from the group consisting of:crystallised PET, PBT, PEN, PEN/PET copolymers, or a blend of any of theforegoing. In a preferred embodiment, PBT is used as the first plasticmaterial.

In yet another embodiment, any of the containers above further comprisea neck, the neck connecting the opening to a main body of the container,and wherein the entire neck of the container is formed of the firstplastic material.

Forming the entire neck of the container from the semi-crystallinematerial may be advantageous in terms of rigidity and also in reducingstrain and stress forces between the parts of the container formed fromthe semi-crystalline material and other material(s).

A further embodiment provides any of the containers above, wherein theentire container is formed of the first plastic material. This may beadvantageous as very few or no stress or strain forces may beexperienced within the body of the container, thus making the containermore stable particularly under pressure and at higher temperatures.

In another embodiment, any of the containers above may having a lipportion, wherein the opening of the container comprises the lip portion,the lip portion adapted to engage with an inverted U-shaped receivingportion of the valve cup.

The problem is also solved by a fluid medium dispensing systemcomprising:

-   -   any of the containers above;    -   a valve; and    -   a valve cup adapted to support the valve and seal the opening of        the container, wherein    -   the valve cup is formed from a second plastic material, and    -   the first plastic material is weldable to the second plastic        material.

As above, reliable sealing may be achieved by ensuring that thecontainer is suitably sealed to the valve cup. Plastic valve cups may beadvantageous for various reasons such as cost and ease of manufacturing.However, some plastic valve cups may be prone to deformation at highertemperatures. Using a plastic valve cup permits welding to the plasticcontainer. Therefore, even if the valve cup deforms, the container isfixed to the valve cup in such a way that the seal therebetween is notbroken. In other words, the seal between the valve cup and container ismaintained.

In some configurations, the rigid part of the container may provide asufficient rigid basis for any deformation of the valve cup to bedirected radially towards the valve supported by the valve cup. In otherwords, the radial forces acting against the rigid part of the containermay cause a compressive force on a part of the valve at the centre ofthe valve cup. This means that the valve may be reliably held and sealedby the valve cup even if the valve cup is formed of a deformableplastic.

In a further embodiment of the system above, the second plastic materialis a polyester, preferably PET.

In another embodiment of any of the systems above, the valve cup isweldable to the container by one of: friction welding, ultrasonicwelding, and laser welding.

In a further embodiment of any of the systems above, the valve cup iswelded to the container, thereby providing a seal between the valve cupand the opening of the container.

The problem is also solved by a valve cup for use with a container fordispensing a fluid medium stored under pressure, the valve cup adaptedto support a valve and to seal an opening of the container, wherein:

-   -   the valve cup is formed from a metal or rigid material, and    -   the valve cup is provided with a polyester lining at at least a        part of the valve cup adapted to contact the container.

In an alternative valve cup, the valve cup may be formed of twomaterials; a metal or rigid material body, and a polyester lining. Themetal or rigid material may be formed from any suitable material thatdoes not deform or warp at temperatures greater than 50° C. That is, therigidity of the valve cup is provided by the metal or rigid material,which thereby ensures that the valve is reliably held and sealed by thevalve cup.

The valve cup also comprises a polyester lining covering at least a partof the metal or rigid material valve cup. Preferably, this part facesthe container when the valve cup is fixed to the container. In this way,the valve cup may be welded to a plastic container, thus enabling a sealbetween the valve cup and the container.

In another embodiment of the valve cup above, the valve cup is formedfrom aluminium and the polyester lining is formed from PET.

In another embodiment of any of the valve cups above, the polyesterlining is coated or held by the valve cup and may be fixed by adhesiveto the valve cup. The polyester lining may be coated directly onto asurface of the valve cup, thus providing a chemical bond between themetal or rigid material and the polyester lining. This may beadvantageous should the polyester lining experience distortion whenheated. Alternatively, the polyester lining may be held by a specificconfiguration of the valve cup, e.g., the valve cup may be shaped so asto be able to crimp or clinch the polyester lining. This provides amechanical configuration, which may be advantageous when coating is notpossible because of the materials chosen, or when the chemical bonds donot sufficiently withstand deformation of the polyester lining.

In another embodiment of any of the valve cups above, the polyesterlining is provided on an underside of the valve cup.

The problem is also solved by a fluid medium dispensing systemcomprising:

-   -   a container for storing a fluid medium under pressure, the        container comprising an opening;    -   a valve; and    -   any of the valve cups above and adapted to support the valve and        seal the opening of the container, wherein    -   the container is formed from a second plastic material, and    -   the polyester lining is weldable to the second plastic material.

As discussed above, reliable sealing may be achieved not only byproviding a rigid valve cup in order to maintain the seal between thevalve cup and the valve, but also by ensuring that the container issuitably sealed to the valve cup. Plastic containers may be advantageousfor various reasons compared to metal containers, e.g., because of costor ease of manufacturing. However, plastic containers may be prone todeformation at higher temperatures, e.g., conventional PET used forbottles. A valve cup comprising a held or coated polyester liningpermits plastic welding to the plastic container. Therefore, even if thecontainer deforms, the container is fixed to the valve cup in such a waythat the seal therebetween is not broken. In other words, the sealbetween the valve cup and container is maintained. Hence, a rigid valvecup comprising a polyester lining provides the ability to make use ofthe advantages of plastic containers, while maintaining the seal betweenthe valve and valve cup.

In a further embodiment of the system above, the second plastic materialis a polyester, preferably PET.

In a further embodiment of the systems above, the valve cup is weldableto the container by one of: friction welding, ultrasonic welding, andlaser welding.

In another embodiment of any of the systems above, the valve cup iswelded to container, thereby providing a seal between the valve cup andthe opening of the container.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an assembled dispensing system in accordance with a firstembodiment of the invention;

FIG. 2a shows a cross-section of the valve cup of FIG. 1;

FIG. 2b shows a top-down view of valve cup in FIG. 2a ;

FIG. 3 shows an exploded view of the valve cup and container of FIG. 1;

FIG. 4 shows a valve cup in accordance with a third embodiment of thepresent invention; and

FIG. 5 shows an exemplary method for assembling a dispensing system.

DETAILED DESCRIPTION First Embodiment

FIG. 1 shows a dispensing system 1 in accordance with the principles ofthe present invention. The dispensing system 1 includes a valve cup 10according to a first embodiment of the invention, a container 30, and avalve 50. Typically, the inner region of the container 30 is pressurisedto a pressure greater than atmospheric pressure. When a fluid medium isstored within the container, this pressure may be 7 bar, although thepressure is not limited to this and may take any desired value limitedonly by regional or governmental restrictions. The valve 50 is generallyheld in a fixed position by the valve cup 10 such that, when a force isapplied to the valve 50 from a user, the valve 50 can be actuated to anopen position. In this position, the pressure difference causes thefluid medium to be distributed from the container 30 via the valve 50.

The valve 50 is shown in detail in FIG. 1, but it should be appreciatedthat any suitable known valve can be substituted for valve 50. In FIG.1, the valve 50 may include a main body 52 which is preferablycylindrical and includes a hollow inner portion. A plunger 53 may alsobe provided and communicates with the hollow inner portion of the mainbody 52. In some embodiments, the plunger 53 may be disposed totallywithin the main body 52, but preferably has a dispensing tip 54protruding away from the main body 52.

The dispensing tip 54 may have any cross-sectional shape but ispreferably cylindrical. The dispensing tip 54 may also include an upperchannel 55 that defines a hollow inner portion of the dispensing tip 54.A through hole 56 may be provided at a lower portion of the dispensingtip 54. In FIG. 1, the through hole 56 extends perpendicularly to theaxis of the upper channel 55, but the through hole 56 is not limited tothis configuration. The main body 52 of the valve 50 may also include alower channel 57 that extends from a lower part of the main body 52. Inone configuration, as seen in FIG. 1, the upper and lower channels 55,57, and the plunger 53 and main body 52 share the same common centralaxis.

The plunger 53 may be provided so as to slide in the direction of thecommon central axis. The plunger 53 may be biased to a closed positionby a spring (not shown) disposed in the hollow portion of the main body52 and communicating with receiving parts, such as perpendicularflanges, of the plunger 53. FIG. 1 shows a possible closed positionwhereby the lower channel 57 is prevented from fluidly communicatingwith the upper channel 55 and through hole 56 by a seal member 60,described in more detail below. To actuate the valve 50, a user mayapply a downward force in the axial direction of the main body 52,thereby causing the plunger 53 to traverse downwards (with respect toFIG. 1) such that the through hole 56 communicates with the hollow partof the main body 52. In this way, the upper and lower channels 55, 57may be in fluid communication in this open position. Based on thepressure difference, the fluid medium can be evacuated from thecontainer 30 through the lower channel 57, the hollow portion of themain body 52, the through hole 56, and finally the upper channel 55. Acap or other directional device may be provided to communicate with thedispensing tip 54 to direct the flow of the fluid medium when exitingthe upper channel 55 as is known in the art.

Optionally, a bag 100 (see FIG. 5) may be attached to the valve 50. Thevalve 50 may have recesses 58 or any other means to allow for attachmentof the bag 100 to the valve 50. Preferably, the bag 100 has an openingthat fits around the lower channel 57 of the valve 50. In this way, theinner volume of the bag 100 may be in fluid communication with the lowerchannel 57 and hence also the upper channel 55 when the valve 50 isactuated. In this optional configuration, the fluid medium may be housedin the bag 100 and the inner volume of the container 30 between thewalls of the container 30 and the bag 100 may be pressurised withpropellant gas. In the alternative, the fluid medium may also act as thepropellant gas in the absence of the bag 100.

The valve 50 is supported by the valve cup 10. In the example of FIG. 1,the valve 50 is centrally mounted in the valve cup 10; that is, thevalve cup 10 and valve 50 share the same central axis. The valve cup 10may have a central opening 11 for such a purpose, as seen in FIG. 2a .However, it should be appreciated that any mounting configuration of thevalve 50 can be employed.

FIGS. 2a and 2b further highlight the exemplary mounting configurationfor mounting the valve 50 to the valve cup 10. The central opening 11may be defined by an inclined portion 13 of the valve cup 10. Theinclined portion 13 may define an outer diameter d1 at its thickestpoint and slope towards the central opening 11, the central opening 11having a diameter smaller than d1.

The diameter d1 is preferably larger that the diameter of the main body52 of the valve 50. In one example configuration, the diameter d1 may be14 mm, but the diameter d1 is not limited to this value. It should alsobe appreciated that the inclined portions 13 do not have to be inclined,but should at least project towards the central opening 11. The inclinedportion 13 may also have a number of first inner projections 12 disposedat the sides facing central opening 11. While FIG. 2b shows eight firstinner projections 12, the present invention is not limited to thisnumber. These first inner projections 12 may communicate with the outerdiameter of the dispensing tip 54 of the valve 50 in order to firmlysupport the dispensing tip 54 as seen in FIG. 1.

The valve main body 52 may be supported by second inner projections 14that, in FIG. 2a , are disposed below the inclined portions 13. In thisway, the valve 50 may be threaded through the valve cup 10 from a lowerside thereof (i.e., starting from the direction where the container 30is positioned in FIG. 1) until the top of the main body 52 abuts eitherthe lower side of the inclined portions 13 or the seal member 60positioned at the lower side of the inclined portions 13. Projections onthe top of the main body 52 as seen in FIG. 1 may also be provided so asto accommodate the seal member 60. A groove 59 in the top part of thevalve main body 52 may also be provided to aid in aligning the sealmember 60, allowing the seal member 60 to flex, and/or equalising thepressure.

The seal member 60 is preferably sized so as to surround the outerdiameter of the dispensing tip 54 and cover the through hole 56 in theclosed position, as seen in FIG. 1. When the plunger 53 is presseddownwards by the user, the seal member 60 may be permitted to flex byvirtue of the groove 59, although this is not essential.

When assembling the valve 50 and valve cup 10, the seal member 60 may beinserted into the lower region of the valve cup 10 defined by the secondinner projections 14, or the seal member 60 may be positioned on top ofthe valve main body 52. In any case, when the valve 50 is threaded intothe valve cup 10 such that the dispensing tip 54 passes through thecentral opening 11, the second inner projections 14 may hold the valvemain body 52 in place. In some embodiments, the second inner projections14 may include raised portions 15 that snap fit into correspondingreceiving portions provided in the valve main body 52. FIG. 1exemplifies this configuration in more detail. This configurationenables the valve 50 to be rigidly held and sealed by the valve cup 10.

The structure of the valve cup 10 is not particularly limited. FIGS. 1,2 a, and 2 b show one exemplary configuration, although the specificconstruction is not limited to that shown. The valve cup 10 may includeinverted U-shaped receiving portions 16 that are adapted to receive alip portion 38 of the container 30. The outer side of the invertedU-shaped receiving portions 16 may define the outer dimension ordiameter d2 of the valve cup 10. Preferably, the diameter d2 is greaterthan outer diameter of an opening 32 of the container 30. In one exampleconfiguration, the diameter d2 may be 34.1 mm, but the diameter d2 isnot limited to this value.

The inverted U-shaped receiving portions 16 may define a space whereinthe inner surfaces of the inverted U-shaped receiving portions 16 maycontact the lip portion 38 of the container 30 when the valve cup 10 isattached to the container 30. The innermost surface of the innersurfaces may define a diameter d3 of the valve cup 10 which may be equalto or less than the inner diameter of the opening 32. In one exampleconfiguration, the diameter d3 may be 24.8 mm, but the diameter d3 isnot limited to this value. In some configurations, the outermost surfaceof the inner surfaces may be provided with a projection 17 extendingtowards the innermost surface. As seen in FIG. 1, the projection 17 maymate with a lower part of the lip portion 38. Preferably, the projection17 facilitates a snap-fit engagement of the valve cup 10 with thecontainer 30 which may improve the ease of the welding process betweenthe valve cup 10 and container 30 by ensuring correct alignment.

The inverted U-shaped receiving portions 16 may have a height h1 than isgreater than the height of the lip portion 38 such that the lip portion38 is completely contained within the inverted U-shaped receivingportions 16. This configuration is seen in FIG. 1. In one exampleconfiguration, the height h1 may be 6.7 mm, but the height h1 is notlimited to this value. The valve cup 10 may also have a section thatconnects the outer part of the inclined portions 13 to the inner part ofthe inverted U-shaped receiving portions 16. This section may define asecond height h2 than is greater than the height h1 such that thesection is positioned below the lip portion 38. In one exampleconfiguration, the height h2 may be 9.25 mm, but the height h2 is notlimited to this value.

The section may also be provided with a number of enforcing members orportions 18 that extend from the inverted U-shaped receiving portions 16to the outer side of the inverted portions 13. This may aid inincreasing the structural rigidity of the valve cup 10 while alsoreducing production costs and material consumption. FIG. 2b shows eightenforcing portions 18 but the number is not limited to this and more orless enforcing portions 18 can be used depending on the desiredstructural requirements. The enforcing portions 18 can be made of thesame material as the valve cup 10 or a different material. The enforcingportions 18 may be integrally formed with the valve cup 10 or formed asseparate components.

As mentioned above, the valve cup 10 is configured to be attached to thecontainer 30. In FIG. 3, the container 30 comprises an opening 32 thatis circular; however, any shaped opening 32 may be used. The container30 may comprise a main body 34 that is connected to the opening 32. Insome preferred configurations, the container 30 may include a neckportion 36 which connects the opening 32 to the main body 34. The lipportion 38 may be provided as part of the neck portion 36 or as aseparate component. The general dimensions of the container 30 are notlimited in any particular manner, aside from the relationships withrespect to the dimensions of the valve cup 10 as mentioned above.

In accordance with the first embodiment of the present invention, thevalve cup 10 is formed from a plastic material that is asemi-crystalline polyester. In this manner, the structural rigidity ofthe valve cup 10 can be ensured beyond the recommended 50° C. owing tothe higher degree of crystallinity. In some cases, the degree ofcrystallinity may be greater than 35%, and preferably greater than 38%when measured using differential scanning calorimetry (DSC). DSC is awell-established method for measuring thermal properties of materialsand is not explained further herein.

One material that can be used for the valve cup 10 of the presentinvention is crystallised PET (CPET). PET can either be amorphous orsemi-crystalline, depending on how it is processed. Typically, PET canbe injection moulded using a suitable mould (e.g., a valve cup). When astandard cycle time is used, the resulting PET product is completelyamorphous. A semi-crystalline plastic is one that displays crystallinestructures but also amorphous regions. When heated, the amorphousregions can transition from a hard and brittle state to a rubbery, soft,and elastic state; the temperature at which this occurs is known as theglass transition temperature. In a semi-crystalline plastic, therigidity of the plastic is proportional to the degree of crystallinity,which essentially defines the percentage of the plastic that exhibitscrystalline structures. Because the crystalline structures do notundergo the transition from hard to rubbery states, the crystallinestructures keep their shape and thus can maintain the rigidity of thesemi-crystalline plastic even when the amorphous regions do make thetransition at the glass transition temperature.

The approximate degree of crystallinity of PET ranges from 30% to 40%,although other percentages may be possible. CPET may be formed byheating virgin PET and allowing the heated PET to cool slowly, moreslowly than prescribed by a standard cycle used in injection moulding,thus forming crystalline structures. Thus, CPET has a high degree ofcrystallinity. In contrast, amorphous PET (APET) is cooled much morequickly preventing the crystalline structures from forming.

CPET may also have nucleating agents added thereto in order to enhancethe formation of crystalline structures in the material. Alternatively,other additives may be introduced to PET in order to increase thestiffness and/or durability, e.g., glass particles or fibres.

Typically, PET films and bottles have a limited degree of crystallinityand usually have small crystallites leading to a clear and transparentmaterial. This is perhaps the most common form of PET. CPET requiresmore careful control when forming and thus can be much more costly toproduce.

CPET is much less subject to deformation under stress, especially atlarger temperatures, than amorphous PET (APET). This is primarilybecause of the rigidity of the crystalline structures therein. Becausesemi-crystalline polyesters include both crystalline and amorphousregions, they can be characterised by a glass transition temperature.For PET, the glass transition temperature is between 67° C. foramorphous PET to 81° C. for semi-crystalline PET. Therefore, in the caseof PET, a higher glass transition temperature correlates with a largerdegree of crystallinity, and thus PET having a higher glass transitiontemperature is desired for use as the valve cup 10, preferably over 74°C.

In a preferential embodiment, polybutylene terephthalate (PBT) is usedas the plastic material of the valve cup 10. PBT is alwayssemi-crystalline in normal commercial settings. Typically, the degree ofcrystallinity is always greater than 30%, and is usually in the range of40% to 50%. Although the glass transition temperature is approximately66° C. for PBT, PBT is generally more rigid that amorphous PET owing tothe higher degree of crystallinity. This makes PBT an excellent choiceof material for use as the valve cup 10.

Yet another material that is suitable is polyethylene napthalate (PEN).PEN is very stable, particularly at higher temperatures. PEN can alsoform a semi-crystalline structure and has a glass transition temperatureof approximately 125° C. Compared to PET, PEN has higher oxygen andwater vapour barrier, tensile strength and flexural modulus. Inaddition, moulding and blowing cycles for PEN are much shorter than forPET leading to increased productivity. However, the cost of PEN is, atpresent, much higher than PET.

It should also be appreciated than many other polyesters may be usedprovided that they display appropriate semi-crystalline properties.Blends of polyesters may also be used. In one example, a PEN/PETcopolymer may be used, wherein the percentage of PEN is relatively lowin comparison to the percentage of PET, e.g., between 10-20% PEN forreasons of cost. Other copolymers may be used such as PET/PBTcopolymers, or even PET/PBT/PEN copolymers. However, any of PET, PBT, orPEN may also be blended with other polyesters and/or other additives,such as nucleating agents, to form semi-crystalline structures.

Moreover, when the valve cup 10 is formed from a semi-crystallinepolyester, the valve cup 10 can be welded to the container 30 when thecontainer is formed of a second plastic material. The welding can beperformed using any suitable technique to weld two plastics together,but is preferably one of friction welding, ultrasonic welding, or laserwelding. In the first embodiment, the container 30 may be formed of PETwith any appropriate degree of crystallinity and subsequently welded tothe valve cup 10. This ensures that the valve cup 10 (e.g., the invertedU-shaped receiving portion 16) does not separate from the container 30(e.g., the lip portion 38) even when deformation of the container 30 athigh temperatures occurs.

In accordance with the first embodiment of the invention, using asemi-crystalline polyester as the material for the valve cup 10 ensuresthat the valve 50 is suitable held by the valve cup 10 at temperaturesover 50° C. because deformation or distortion of the valve cup 10 doesnot occur. In addition, using a semi-crystalline polyester as thematerial for the valve cup 10 means that a plastic container 30 can bewelded to the valve cup 10 thus ensuring that the seal between thecontainer 30 and valve cup 10 is maintained even if deformation of thecontainer 30 occurs. Thus, the advantageous properties of PET when usedas the container 30 can be retained without compromising sealingperformance at higher temperatures.

It should be appreciated, however, that the material of the container 30is not limited to PET but may be any suitable polyester and may also beformed of any of the semi-crystalline polyesters above.

As discussed above, the rigidity of the valve cup 10 can also beimproved by using the enforcing members 18. The enforcing members 18 maybe formed of the same semi-crystalline polyester or may be formed of adifferent material, e.g., metal.

It should be appreciated that various modifications to the specificstructure of the valve cup 10, container 30, and valve 50 may be madewhile still conforming to the principles of the first embodiment of theinvention.

Second Embodiment

The second embodiment of the invention may be the same as the firstembodiment, but vary only in the materials used for the container 30 andvalve cup 10. That is, any structural features described in the firstembodiment may equally be present in the second embodiment.

In the second embodiment, a part of the container 30 may be formed fromany of the semi-crystalline polyesters used for the valve cup 10 of thefirst embodiment. Specifically, a part adjacent or in contact with theopening 32 of the container 30 is preferably formed from thesemi-crystalline polyester. In contrast, the valve cup 10 may be formedfrom any polyester, such as PET.

In the second embodiment, the opening 32 of the container 30 maintainsits rigidity at temperatures exceeding 50° C. by virtue of being formedfrom the semi-crystalline polyester. The valve cup 10 may maintain theseal with respect to the valve 50 due to the compressive forces actingradially inward from the opening 32 of the container 30 if the valve cup10 begins to deform at higher temperatures.

Alternatively, the valve cup 10 may be structured in such a manner as tochannel any deformation to areas away from the valve 50, i.e., away frominclined portion 13. For example, with reference to FIG. 2a , thedifference in heights h1 and h2 may aid in channelling any deformationto be concentrated in the sections connecting the inverted U-shapedreceiving portion 16 and the inclined portion 13. Other structuralconfigurations may also be considered. In some cases, the enforcingmembers 18 may be configured to prevent any deformation of the valve cup10 at locations surrounding the valve 50.

In the second embodiment, the container 30 is preferably formed from thesemi-crystalline polyester only at a portion adjacent or in contact withthe opening 32. This may include only the lip portion 38. Alternatively,the entire neck portion 36 and lip portion 38 may be made from thesemi-crystalline polyester. In other configurations, the entirecontainer 30 may be formed from the semi-crystalline polyester, althoughthis may increase the costs and/or difficulty of the manufacturingprocesses associated with forming the container 30.

As with the first embodiment, in accordance with the second embodimentof the invention, using a semi-crystalline polyester as the material forat least a part of the container 30 ensures that the valve cup 10 issuitably held by the container 30 at temperatures over 50° C. becausedeformation or distortion of the opening 32 of container 30 does notoccur. This can limit or appropriately deflect any deformation of thevalve cup 10 meaning that the valve 50 is stably held. In addition,using a semi-crystalline polyester as the material for a part proximateto the opening 32 of the container 30 means that a polyester valve cup10 can be welded to the container 30 thus ensuring that the seal betweenthe container 30 and valve cup 10 is maintained even if deformation ofthe valve cup 10 occurs.

The advantageous properties of using PET when used as the valve cup 10and potentially as part of the container 30 can be retained withoutcompromising sealing performance at higher temperatures.

It should be appreciated, however, that the material of the valve cup 10is not limited to PET but may be any suitable polyester and may also beformed of any of the semi-crystalline polyesters above.

Third Embodiment

In the third embodiment, the primary material of the valve cup 10 may bea metal or other rigid material. Preferably, the primary material isaluminium. The structure of the valve cup 10 may be the same as in thefirst embodiment.

FIG. 4 shows an example of the valve cup 10 in accordance with the thirdembodiment of the present invention. In FIG. 4, a polyester lining 70may be provided on a surface of the valve cup 10, preferably at aportion that contacts the container 30. The polyester lining 70 may beformed only in a region that contacts the container 30, e.g., on theinner surfaces of the inverted U-shaped receiving portion 16, or may beformed entirely on the lower surface of the valve cup 10. Additionally,the polyester lining 70 may be coated on the valve cup 10, or may be aseparate component that is subsequently attached to via adhesive and/orheld by the valve cup 10. In this regard, the valve cup 10 may beconfigured to clamp or hold a part of the polyester lining 70.

The polyester lining 70 may be formed from any polyester, but ispreferably formed from PET. When the valve cup 10 is formed of a metal,i.e., aluminium, or other rigid material, the structural rigidity of thevalve cup 10 at temperatures greater than 50° C. is ensured by thestructural rigidity of the metal or rigid material. In other words, themetal or rigid material does not deform at temperatures greater than 50°C. This means that the valve cup 10 may reliably hold and seal the valve50.

Providing the polyester lining 70 on a part of the valve cup 10 meansthat the polyester lining 70 can be welded using any of theaforementioned techniques to a polyester based container 30, e.g., thecontainer 30 of the first embodiment. In this way, the valve cup 10 canbe reliably attached to the container 30 such that any deformation ofthe container 30 at temperatures greater than 50° C. does not cause thevalve cup 10 and container 30 to separate, and thus the sealtherebetween is maintained.

The advantageous effects described in both the first and secondembodiments can therefore be realised by the third embodiment; namely,that the seal between the valve 50 and valve cup 10 and the seal betweenthe valve cup 10 and container 30 can be maintained at temperaturesgreater than 50° C.

As seen in FIG. 4, the polyester lining 70 may also be provided withprojections 77 similar to the projections 17 of the first embodiment.The projections 77 may be formed additionally as part of the polyesterlining 70, i.e., varying thickness of the polyester lining 70, or theymay be formed as a natural consequence of following the projections 17when coating the valve cup 10.

The polyester lining 70 does not have to be formed from thesemi-crystalline polyesters as discussed in the first and secondembodiments. However, in some cases, to prevent deformation of thepolyester lining 70 that may lead to detachment from the valve cup 10,the polyester lining 70 may be formed from the semi-crystallinepolyesters.

Method for Assembling Dispensing System

A method of assembling the dispensing system using valve cups 10according to any of the first through third embodiments is nowdescribed.

FIG. 5 exemplifies a method of assembling the dispensing system.Initially, the valve 50 is coupled to the valve cup 10. An exemplarymethod for performing this coupling has been described with respect tothe first embodiment, and so will not be repeated here. Essentially anymethod or coupling may be performed depending upon the exact structureof the valve 50 and the valve cup 10.

A first step, as shown in FIG. 5(a), involves coupling the bag 100 tothe valve 50. More specifically, an opening of the bag 100 is attachedto a lower part of the valve 50, e.g., lower channel 57, such that thevalve 50 can be in fluid communication with the interior of the bag 100when actuated. The valve 50 may be provided with any means forfacilitating this coupling, such as the recesses 58 in FIG. 1. The bag100 may be secured by any suitable means such as adhesive, welding, orclamping. The combination of bag 100 and valve 50 in a fixed arrangementis generally referred to as a Bag On Valve (BOV). The bag 100 ispreferably liquid, gas, or fluid impermeable.

Once the bag 100 is securely attached to the valve 50, the bag 100 maybe folded to reduce the footprint thereof. As shown in FIG. 5(b), thebag 100 may be folded in such a way that the footprint is less than thediameter of the valve cup 10. Preferably, the footprint is less than thediameter of the opening 32 of a container 30 to which the valve cup 10is to be assembled such that the BOV may be inserted into the opening32. In an exemplary method, the BOV is folded such that the footprinthas a diameter d4 less than 25 mm or 22 mm, although other diameters arepossible.

The folding may be performed in any manner so as to reduce the footprintof the BOV and allow insertion into the container 30. In one example,the flat bag 100 is rolled around the axis of the valve 50 and valve cup10 such that the bag 100 is in a spiralled configuration centred on theaxis of the valve 50. In another example, the bag 100 may be folded in aconcertina. In both cases, the BOV is preferably provided with asuitable footprint.

In contrast to known methods, the BOV may not be provided with acontaining sleeve or tape to retain the BOV in the folded configuration.Rather, the folded BOV is preferably inserted directly into thecontainer 30, as is shown in FIG. 5(c). In this step, the BOV is slidthrough the opening 32 of the container 30 while maintained in thefolded state to improve the ease of insertion.

Once partially inserted, the inner region of the container 30 may befilled with gas, preferably a propellant gas. Suitable propellant gassesare known in the art and are not discussed further herein. The methodused is preferably undercup gassing, which essentially means that thegas is passed under the valve cup 10 and into the region between the bag100 and the inner volume of the container 30. In the present invention,the inner volume of the container 30 may be pressurised to a pressurebetween 1 to 3 bar, preferably 1.5 to 2.5 bar.

As seen in FIG. 5(d), once the gassing is complete, the BOV is insertedinto the container 30 such that valve cup 10 contacts the opening 32 ofthe container 30.

In a preferred configuration, the valve cup 10 is provided with theinverter U-shaped receiving portion 16 and the container 30 is providedwith the lip portion 38. Thus, the BOV may be inserted into thecontainer 30 until the lip portion 38 of the container 30 abuts theinverted U-shaped receiving portion 16.

In a more preferably configuration, the inverted U-shaped receivingportion 16 comprises the projections 17, 77 which are adapted to engagein a snap-fit manner with the underside of the lip portion 38. In thisway, when the valve cup 10 is pressed onto the lip portion of thecontainer 30, the U-shaped receiving portion 16 may deform slightly toallow the projections 17, 77 to pass over the lip portion 38 andsubsequently return to their resting state once the projections 17, 77have passed over the lip portion 38. Securing the valve cup 10 in thisway aids in ensuring that the welding process is performed with improvedaccuracy as the valve cup 10 can be reliably aligned with the container30.

As seen in FIG. 5(e), a welding head 110 may be positioned over thevalve cup 10 in order to weld the valve cup 10 to the container 30. Asdescribed in the first through third embodiments, the valve cup 10 andcontainer 30 may be formed, at least in part, from polyesters. Thismeans that welding, such as friction welding, ultrasonic welding, orlaser welding, can be performed so as to weld the valve cup 10 to thecontainer 30. Any of the welding techniques can be used and thesetechniques are generally known in the art and so are not described inany further detail herein.

Once the welding is completed, the dispensing system 1 is assembled.Further assembly steps may be possible, such as adding a protectionovercap 120 to cover the exposed part of the valve 50 as seen in FIG.5(f). The assembled dispensing systems 1 may then be transported tovarious consumers to be filled with a variety of different products. Tofill the dispensing systems, the fluid medium to be dispensed is passedthrough the valve 50 into the bag 100, i.e., via upper channel 55,through hole 56, and lower channel 57. The pressure in the container 30increases as the bag 100 fills with the fluid medium. Preferably, thepressure increases to around 6 to 8 bar, preferably 6.5 to 7.5 bar. Thisincrease in pressure aids in dispensing the fluid medium when the valve50 is actuated by a user.

It should be noted that some or all of the steps of the method may beperformed in a sealed environment. This may aid in assembling thedispensing system 1 when the pressure is increased.

According to this method, the dispensing systems are assembled bywelding the valve cup 10 to the container 30 after experiencing undercupgassing. Conventional methods rely on clinching the valve cup to thecontainer, whereas the present assembly method utilises the welding of aspecially modified valve cup 10 to a container 30. The welding may alsobe performed at lower pressures and without the presence of the fluidmedium to the dispensed. This can ensure a more reliable weld andpotentially prevent any contamination of the fluid medium to bedispensed.

The present invention therefore provides a valve cup 10 or container 30that is modified to be rigid at temperatures exceeding 50° C., whilealso allowing for welding between the valve cup 10 and container 30.Primarily, this can be achieved by using either a semi-crystallinepolyester with a high degree of crystallinity, or by making use of apolyester layer on a metal or rigid material valve cup. A method ofassembling a dispensing system including these components is alsoprovided.

1. A valve cup for use with a container for dispensing a fluid mediumstored under pressure, the valve cup adapted to support a valve and toseal an opening of the container, wherein: the valve cup is formed froma first plastic material that is a semi-crystalline polyester.
 2. Thevalve cup of claim 1, wherein the first plastic material has a degree ofcrystallinity greater than 35%, preferably greater than 38%, whenmeasured using differential scanning calorimetry.
 3. The valve cup ofclaim 1, wherein the first plastic material is selected from the groupconsisting of: crystallised PET, PBT, PEN, PEN/PET copolymers, or ablend of any of the foregoing.
 4. The valve cup of claim 1, wherein thevalve cup comprises a central opening that is adapted to receive andsupport the valve and wherein the valve cup comprises one or moreenforcing members radially protruding from the central opening, the oneor more enforcing members adapted to increase the rigidity of the valvecup.
 5. The valve cup of claim 1, wherein the valve cup comprises aninverted U-shaped receiving portion configured to receive a lip portionof the container.
 6. The valve cup of claim 1, in particular claim 5,wherein the inverted U-shaped receiving portion comprises at least oneprotrusion on a surface facing the container when receiving the lipportion, the protrusion adapted to frictionally engage the lip portion.7. A fluid medium dispensing system comprising: a container for storinga fluid medium under pressure, the container comprising an opening; avalve; and the valve cup of claim 1 adapted to support the valve andseal the opening of the container, wherein the container is formed froma second plastic material, and the first plastic material is weldable tothe second plastic material.
 8. The system of claim 7, wherein thesecond plastic material is a polyester, preferably PET.
 9. The system ofclaim 7, wherein the valve cup is weldable to the container by one of:friction welding, ultrasonic welding, and laser welding.
 10. The systemof claim 7, wherein the valve cup is welded to container, therebyproviding a seal between the valve cup and the opening of the container.11. A container for dispensing a fluid medium stored under pressure andcomprising an opening, the container for use with a valve cup supportinga valve sealing the opening of the container, wherein at least a part ofthe container adjacent the opening is formed from a first plasticmaterial that is a semi-crystalline polyester.
 12. The container ofclaim 11, wherein the first plastic material has a degree ofcrystallinity greater than 35%, preferably greater than 38%, whenmeasured using differential scanning calorimetry.
 13. The container ofclaim 11, wherein the first plastic material is selected from the groupconsisting of: crystallised PET, PBT, PEN, PEN/PET copolymers, or ablend of any of the foregoing.
 14. The container of claim 11, whereinthe container comprises a neck, the neck connecting the opening to amain body of the container, and wherein the entire neck of the containeris formed of the first plastic material.
 15. The container of claim 11,wherein the entire container is formed of the first plastic material.16. The container of claim 11, wherein the opening of the containercomprises a lip portion, the lip portion adapted to engage with aninverted U-shaped receiving portion of the valve cup.
 17. A fluid mediumdispensing system comprising: the container of claim 11; a valve; and avalve cup adapted to support the valve and seal the opening of thecontainer, wherein the valve cup is formed from a second plasticmaterial, and the first plastic material is weldable to the secondplastic material.
 18. The system of claim 17, wherein the second plasticmaterial is a polyester, preferably PET.
 19. The system of claim 17,wherein the valve cup is weldable to the container by one of: frictionwelding, ultrasonic welding, and laser welding.
 20. The system of claim17, wherein the valve cup is welded to the container, thereby providinga seal between the valve cup and the opening of the container.
 21. Avalve cup for use with a container for dispensing a fluid medium storedunder pressure, the valve cup adapted to support a valve and to seal anopening of the container, wherein: the valve cup is formed from a metalor rigid material, and the valve cup is provided with a polyester liningat at least a part of the valve cup adapted to contact the container.22. The valve cup according to claim 21, wherein the valve cup is formedfrom aluminium and the polyester lining is formed from PET.
 23. Thevalve cup according to claim 21, wherein the polyester lining is coatedor fixed by adhesive to the valve cup.
 24. The valve cup according toclaim 21, wherein the polyester lining is provided on an underside ofthe valve cup.
 25. A fluid medium dispensing system comprising: acontainer for storing a fluid medium under pressure, the containercomprising an opening; a valve; and the valve cup of claim 21 adapted tosupport the valve and seal the opening of the container, wherein thecontainer is formed from a second plastic material, and the polyesterlining is weldable to the second plastic material.
 26. The system ofclaim 24, wherein the second plastic material is a polyester, preferablyPET.
 27. The system of claim 24, wherein the valve cup is weldable tothe container by one of: friction welding, ultrasonic welding, and laserwelding.
 28. The system of claim 24, wherein the valve cup is welded tocontainer, thereby providing a seal between the valve cup and theopening of the container.